Solution polymers formed from methylene malonate monomers, polymerization, and solution polymer products

ABSTRACT

The present teachings show that it is possible to polymerize 1,1-disubstituted alkene compounds in a solution (for example using one or more solvents). Polymerization of 1,1-disubstituted alkene compounds in a solution provides opportunities to better control the polymerization compared with bulk polymerization. The solution polymerization techniques can be employed for preparing homopolymers, copolymers (e.g., random copolymers), and block copolymers.

CLAIM OF PRIORITY

The present application is a continuation patent application of U.S.patent application Ser. No. 14/966,247 filed on Dec. 11, 2015. Thepresent application claims priority to U.S. patent application Ser. No.14/966,247 filed on Dec. 11, 2015, U.S. patent application Ser. No.14/810,741 filed on Jul. 8, 2015 (granted as U.S. Pat. No. 9,279,022),U.S. patent application Ser. No. 14/789,178 filed on Jul. 1, 2015(granted as U.S. Pat. No. 9,249,265), and U.S. Provisional PatentApplications Nos. 62/186,479 filed on Jun. 30, 2015, 62/182,076 filed onJun. 19, 2015, 62/047,283 filed on Sep. 9, 2014, and 62/047,328 filed onSep. 8, 2014, each incorporated herein by reference in its entirety.

RELATED PATENT APPLICATIONS

The present patent application is related to U.S. patent applicationSer. No. 14/966,409 field on Dec. 11, 2015, Ser. No. 15/467,330 filed onMar. 23, 2017, Ser. No. 15/467,597 filed on Mar. 23, 2017, and Ser. No.15/509,403 filed on Mar. 7, 2017.

FIELD

The teachings herein are directed at polymers including one or more1,1-disubstituted alkene compounds having a hydrocarbyl group bonded tothe carbonyl groups through a direct bond or through an oxygen atom,methods for preparing the polymers in solution, compositions includingthe polymers, and the use of the polymers. The polymers may behomopolymers consisting essentially of (e.g., about 99 weight percent ormore) or entirely of a single monomer or may be copolymers including twoor more monomers (e.g., a random copolymer or a block copolymer having aplurality of polymer blocks). The polymer preferably is prepared byanionic polymerization of one or more reactive 1,1-disubstituted alkenemonomers in solution.

BACKGROUND

Polymerization of 1,1-disubstituted alkene compounds are typicallyperformed in bulk state, and frequently in situ, such as when monomer isplaced between two substrates to be adhered. The resultingpolymerization process may be difficult to control resulting in variableperformance or mechanical properties. For example, the polymerizationprocess may be characterized by one or more spikes in temperature duringthe polymerization process, such as by an increase in temperature ofabout 15° C. or more, about 30° C. or more, or even about 45° C. or more(e.g., during a polymerization reaction). Such an increase intemperature may occur in a short time period (e.g., less than 10minutes, less than 3 minutes, or even less than 1 minute). Typically,the resulting polymer may be characterized by one or more of thefollowing: a generally high level of branching, a high polydispersityindex, a high concentration of non-polymer reaction products, a highconcentration of monomers and/or oligomers, or a generally highviscosity. For example, when polymerized in bulk, the resulting polymermay have a high viscosity that makes further processing, handling, orpolymerization difficult.

As used herein, bulk polymerization refers to the polymerization of apolymerizable composition including one or more monomers where theconcentration of the one or more monomers is about 80 weight percent ormore, preferably about 90 weight percent or more (e.g., about 100 weightpercent), based on the total weight of the compounds in thepolymerizable composition that are liquid at room temperature. Thesepolymerizations typically also require an input of energy either in theform of heat or radiation to initiate polymerization.

Free radical polymerization of dialkyl methylene malonate monomers usingheat, UV light and peroxide is described in U.S. Pat. Nos. 2,330,033 and2,403,791, both incorporated herein by reference. In these patents, themonomer was prepared using traditional methods which results in lowpurity monomer. The polymer examples in these patents are all preparedvia bulk polymerization. One would therefore not expect to be able tocontrol polymer properties, such as molecular weight and molecularweight distribution.

However, while earlier methods for producing certain methylene malonateshave been known in the art, these prior methods suffer significantdeficiencies that preclude their use in obtaining commercially viablemonomers. Such deficiencies include unwanted polymerization of themonomers during synthesis (e.g., formation of polymers or oligomers oralternative complexes), formation of undesirable side products (e.g.,ketals or other latent acid-forming species which impede rapidpolymerization), degradation of the product, insufficient and/or lowyields, and ineffective and/or poorly functioning monomer product (e.g.,poor adhesive characteristics, stability, or other functionalcharacteristics), among other problems. The overall poorer yield,quality, and chemical performance of the monomer products formed byprior methods have impinged on their practical use in the production ofthe above commercial and industrial products.

Polymerization of 1,1-disubstituted alkene compounds using anionicpolymerization processes are useful in the bulk polymerization of1,1-disubstituted alkene compounds and processes which can operate at ornear ambient conditions (starting conditions) have been disclosed. Suchanionic bulk polymerizations may be initiated using a wide range ofinitiators, and may even be initiated by contact with certainsubstrates. Other bulk polymerization reactions may be initiated by UVlight. However, as discussed above, the bulk polymerization may limitthe ability to control the structure of the polymer molecules and/or tobe able to easily handle the resulting polymer composition or product.These difficulties in bulk polymerization may be particularly pronouncedwhen manufacturing large quantities of polymer, where heat transportissues may occur, especially when there may be shear heat generated bythe flow of the high viscosity polymer and/or heat emitted due to theinherent exothermic nature of the polymerization.

Bulk polymerization of 1,1-disubstituted alkene compounds also present achallenge when attempting to control the structure of the polymer byincluding one or more comonomers. For example, the high viscosity of theintermediate polymer may present difficulties in preparing a blockcopolymer (such as by sequential addition of a first monomer systemfollowed by a second monomer system into a reaction vessel). Otherproblems may arise when attempting to control the structure of a randomcopolymer, where the reaction rates of the different monomers differ sothat the monomers are not uniformly distributed along the length of thepolymer molecular. For example, copolymers including one or more1,1-disubstituted alkene compounds prepared by bulk polymerization aretypically expected to have a generally blocky sequence distributionand/or result in polymer molecules having a broad distribution ofmonomer compositions. As used herein, a copolymer having a generallyblocky sequence distribution of monomers may be characterized as havinga blockiness index of about 0.7 or less, about 0.6 or less or about 0.5or less, or about 0.4 or less.

Although solution polymerization processes have been employed in freeradical polymerization process to better control the polymerarchitecture, such processes have not generally been employed in anionicpolymerization of 1,1-disubstituted alkenes.

When a solution polymerization system is employed with anionicpolymerization methods, sub-ambient temperatures (e.g., less than 10°C., less than 0° C., or less than −20° C. are typically required tocontrol the reaction. As such, in solution polymerization systems it maybe necessary to use a cooling systems and/or insulation for achievingand/or maintain such a low reaction temperature.

Additional difficulties in polymerization of 1,1-disubstituted alkenecompounds arise from the possibility of the anionic group of the growingpolymer reacting with an acid thereby terminating the reaction.Therefore, one would avoid using an acid in polymerizing1,1-disubstituted alkene compounds using anionic polymerization.

Prior attempts at anionic polymerization processes (e.g., bulkpolymerization processes) for 1,1-disubstituted alkene compoundsgenerally have had one or more of the following drawbacks: (1)requirement that the systems have low polymer concentrations; (2) havelacked reproducibility for controlling molecular weight distribution, or(3) have undesirable reactant by-products.

There is a need for polymerization methods, systems, and resultingpolymer compositions or products that allow for improved control of oneor more of the following properties of a polymer containing one or more1,1-disubstituted alkene compounds: the weight average molecular weight,the number average molecular weight, the polydispersity index, thezero-shear viscosity of the polymer (e.g., at one or more temperaturesof at least about 20° C. above the melting temperature of the polymer),the viscosity of the polymer system (e.g., the bulk polymer or thepolymer solution) at room temperature, the sequence distribution ofmonomers in a random copolymer, or having at least two different polymerblocks covalently bonded (e.g., each containing one or more1,1-disubstituted alkene compounds). There is also a need forpolymerization process which can be scaled-up (e.g., to a reactor ofabout 20 liters or more, or having a throughput of about 10 kg ofpolymer per hour or more. There is also a need for processes that resultin a solution containing the polymer. Such solutions may be useful forapplications such as paints, coatings, finishes, polishes, andadhesives. For example, there may be a need for process and polymersystems that result in a solution having a controlled viscosity and/orpolymer concentration.

SUMMARY

One aspect of the disclosure is directed at a process comprising thesteps of: mixing two or more monomers (including a first monomer that isa 1,1-disubstituted alkene compound, and a second monomer different fromthe first monomer) and a solvent; adding an activator; reacting theactivator with the one of the two or more monomers (e.g., with the firstmonomer, or with the second monomer) for initiating the anionicpolymerization of the two or more monomers; and anionically polymerizingthe two or more monomers to form a polymer having a weight averagemolecular weight and/or a number average molecular weight of about 2000daltons or more (preferably about 3000 daltons or more), the polymerincluding the first monomer and the second monomer. The second monomermay be a 1,1-disubstituted alkene compound or a different monomercapable of copolymerizing with the first monomer. Preferably the polymeris a random copolymer. The concentration of the solvent typically isabout 25 weight percent or more, based on the total weight of thesolvent and the two or more monomers.

Another aspect of the disclosure is directed at a process comprising thesteps of: mixing at least a first monomer and a solvent to form asolution including the first monomer and the solvent; wherein the firstmonomer is a first 1,1-disubstituted alkene compound; adding aninitiator; anionically polymerizing the first monomer in the presence ofthe solvent to form a first polymer block including the first1,1-disubstituted alkene compound and having a weight average molecularweight or a number average molecular weight of about 1000 daltons ormore, wherein the first polymer block has a reactive end; afterpolymerizing the first polymer block, adding at least a second monomerto the solvent to form a solution including the second monomer and thesolvent, wherein the second monomer is different from the first monomer(e.g., the second monomer is a second 1,1-disubstituted alkene compounddifferent from the first 1,1-disubstituted alkene compound; reacting thesecond monomer to the reactive end of the first polymer block; andanionically polymerizing the second monomer to form a second polymerblock. The second polymer block includes the second monomer andpreferably has a weight average molecular weight or number averagemolecular weight of about 1000 daltons or more. The second polymer blockmay have a reactive end. The second polymer block has a compositiondifferent from the composition of the first polymer block. Theconcentration of the solvent typically is about 25 weight percent ormore, based on the total weight of the solvent and the two or moremonomers. The block copolymer may be a diblock copolymer or may have oneor more additional polymer blocks (e.g., 3 or more blocks). The firstpolymer block and/or the second polymer block may include one or moreadditional monomers (e.g., different from the first 1,1-disubstitutedalkene compound, and different from the second monomer).

Another aspect of the disclosure is directed at a process comprising thesteps of: mixing one or more monomers (including a first monomer that isa 1,1-disubstituted alkene compound) and a solvent; adding an activator;reacting the activator with one of the one or more monomers (e.g., withthe first monomer) for initiating the anionic polymerization of the oneor more monomers; and anionically polymerizing the one or more monomersto form a polymer having a weight average molecular weight and/or anumber average molecular weight of about 2000 daltons or more, thepolymer including the first monomer, wherein the first monomer isprovided as a high purity monomer having a purity of about 95 weightpercent or more. Preferably the high purity monomer has a purity ofabout 97 weight percent, even more preferably about 99 weight percent.For example, the high purity monomer may include the 1,1-disubstitutedalkene compound having an alkene group and the total concentration ofany analogous compound (i.e., impurity compound) having the alkene groupreplaced by hydroxyalkyl group is about 3 mole percent or less(preferably about 1 mole percent or less, even more preferably about 0.1mole percent or less, and most preferably about 0.01 mole percent orless), based on the total moles of the 1,1-disubstituted alkenecompound. The concentration of the solvent typically is about 25 weightpercent or more, based on the total weight of the solvent and the two ormore monomers.

Another aspect of the disclosure is directed at a polymer including oneor more 1,1-disubstituted alkene monomers. The polymer may be preparedusing a solution polymerization reaction, such as a reaction accordingto the teachings herein.

Another aspect of the disclosure is directed at a polymeric compositioncomprising (1) a polymer including one or more 1,1-disubstituted alkenemonomers and (2) one or more additives.

Another aspect of the disclosure is directed at a system forpolymerizing one or more monomers including a reactor having anagitation device for mixing a monomer and a solvent; about 25 weightpercent or more solvent; and about 2 weight percent or more of one ormore monomers including one or more 1,1-disubstituted alkenes.Preferably the agitation device includes a stirring device. The systempreferably includes an activator(s) for initiating anionicpolymerization of 1,1-disubstituted alkenes.

Another aspect of the disclosure is directed at a block copolymer havinga first polymer block including a first primary monomer that is a1,1-disubstituted alkene compound, wherein the first primary monomer ispresent at a concentration of about 50 weight percent or more, based onthe total weight of the first polymer block, the first polymer blockcovalently bonded to a second polymer block including a second primarymonomer different from the first primary monomer, wherein the secondprimary monomer is present at a concentration of about 50 weight percentor more, based on the total weight of the second polymer block.

Another aspect of the disclosure is directed at a low molecular weightpolymer having a number average degree of polymerization from about 4 toabout 50 and/or a number average molecular weight from about 600 daltonsto about 10000 daltons (e.g., from about 800 to about 8500 daltons). Thelow molecular weight polymer includes about 60 weight percent or more ofone or more 1,1-disubstituted alkene compounds, based on the totalweight of the low molecular weight polymer. Preferably the low molecularweight polymer includes a primary monomer present at about 90 weightpercent or more, based on the total weight of the low molecular weightpolymer, and the primary monomer is one of the one or more1,1-disubstituted alkene compounds. The low molecular weight polymerpreferably has a polydispersity index of about 5 or less.

The methods according to the teachings herein may be employed to producea polymer including one or more 1,1-disubstituted alkene monomers havingimproved control of molecular weight, improved control of molecularweight distribution, or both. For example, a solution polymerizationmethod (such as one according to the teachings herein) may be employedfor controllably producing low molecular weight polymers including a1,1-disubstituted alkene monomer. The methods according to the teachingsherein may be employed to controllably produce high molecular weightpolymers including a 1,1-disubstituted alkene compound. The methodsaccording to the teachings herein may be employed to produce a randomcopolymer including two or more 1,1-disubstituted alkene monomers havingimproved control of the monomer sequence distribution. The methodsaccording to the teachings herein may be employed to produce a blockcopolymer including two different polymer blocks, the block copolymerincluding one or more 1,1-disubstituted alkene monomers. The methodsaccording to the teachings herein may be employed to produce a solutionhaving generally high polymer concentration (e.g., about 2 weightpercent or more, or about 5 weight percent or more) and/or having lowviscosity. The methods according to the teachings herein may be employedto produce polymers using anionic polymerization with a throughput rateof about 10 kg/hour or more and/or in a reactor system having a volume(e.g., of the solution) of about 20 liter or more. For example, themethods according to the teachings herein may better control thetemperature during the polymerization, even when using pilot scale ormanufacturing scale production (e.g., so that the process is generallyfree of temperature spikes during polymerization).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing illustrating features of a system for solutionpolymerization of a polymer including a 1,1-disubstituted alkene monomeraccording to the teachings herein using anionic polymerization.

FIG. 2 is a diagram illustrating features of a process forpolymerization of a polymer including a 1,1-disubstituted alkene monomerusing anionic polymerization.

FIGS. 3A and 3B depict representative NMR spectrograms illustrating theconversion of monomer to polymer via solution polymerization. FIG. 3A istaken at an early stage of the polymerization reaction and the peak at6.45 ppm identifies the presence of unreacted monomer.

FIG. 3B is taken at a later stage of the polymerization reaction andthere is no detectable peak at 6.45 ppm.

FIGS. 4A, 4B, and 4C are differential scanning calorimetry (DSC) curvesof polymers prepared by anionic polymerization in solution according tothe teachings herein, measured at a heating rate of about 10° C./minusing a sample size of about 7 mg showing the glass transitiontemperature of the polymer. FIG. 4A is a DSC curve of a homopolymer of2-phenyl-1-propanol ethyl methylene malonate. FIG. 4B is a DSC curve ofa homopolymer of fenchyl methyl methylene malonate. FIG. 4C is a DSCcurve of a random copolymer of 2-phenyl-1-propanol ethyl methylenemalonate (about 50 weight percent) and fenchyl methyl methylene malonate(about 50 weight percent).

DETAILED DESCRIPTION

Surprisingly, it has been found that a monomer including a1,1-disubstituted alkene may be anionically polymerized using a solutionpolymerization process_to controllably produce polymers (e.g., toproduce polymers having controlled molecular weight and/or structure).In the solution polymerization process, the monomers are diluted by asolvent and the monomer and solvent form a single continuous phase.During the polymerization process the resulting polymer may be solublein the solvent, or may precipitate from the solvent. Preferably, thepolymer is soluble in the solvent during some or all of thepolymerization process. For example, the solvent and/or the reactionconditions (such as the solvent concentration, the polymerizationtemperature) may be selected so that the polymer is soluble in thesolvent during some or all of the polymerization process. The methodsaccording to the teachings herein may be used to prepare a homopolymeror a copolymer. For example, the polymer may be a random copolymer or ablock copolymer.

FIG. 1 illustrates features that may be employed in a solutionpolymerization system according to the teachings herein. The solutionpolymerization system 10 includes a continuous liquid phase 18 andoptionally a dispersed polymer precipitate phase 20 (not shown). It willbe appreciated that prior to a polymerization reaction, the liquid phasemay include solvent 12, monomer 14 and be substantially free of anypolymer 26. The polymerization may start (i.e., initiate) with theaddition of activator 16. It will be appreciated that the activator 16may be reapidly consumed during the initation reaction. After apolymerization reaction begins, the polymer 26 may initially be in theliquid phase 18. As the polymer molecules grow, some or all of thepolymer 26 may optionally precipitate out of the liquid phase 18 into adispersed phase 20 (not shown). If a dispersed polymer phase 20 isformed, the dispersed phase may include the polymer 26 and optionally aportion of the monomer 14 and/or a portion of the solvent 12. Themonomer 14 may be completely converted so that eventually thepolymerization system 10 includes polymer 26 and is substantially orentirely free of monomer 14. The continuous liquid phase 18 may includeor consist substantially (e.g., about 90 volume percent or more or about98 volume percent or more based on the total volume of the continuousliquid phase) of the solvent 12, the monomer 14, and the polymer 26. Themonomer 14 and/or polymer 26 preferably includes one or more1,1-disubstituted alkene compounds (e.g., one or more 1,1-disubstitutedethylene compounds).

The monomer typically includes one or more 1,1-disubstituted alkenecompounds (e.g., one or more 1,1-disubstituted ethylene compounds). The1,1-disubstituted alkene preferably is a primary monomer (i.e., amonomer present at 50 weight percent or more of a polymer block or of anentire polymer). 1,1-disubstituted alkene compounds are compounds (e.g.,monomers) wherein a central carbon atom is doubly bonded to anothercarbon atom to form an ethylene group. The central carbon atom isfurther bonded to two carbonyl groups. Each carbonyl group is bonded toa hydrocarbyl group through a direct bond or an oxygen atom. Where thehydrocarbyl group is bonded to the carbonyl group through a direct bond,a keto group is formed. Where the hydrocarbyl group is bonded to thecarbonyl group through an oxygen atom, an ester group is formed. The1,1-disubstituted alkene preferably has a structure as shown below inFormula I, where X¹ and X² are an oxygen atom or a direct bond, andwhere R¹ and R² are each hydrocarbyl groups that may be the same ordifferent. Both X¹ and X² may be oxygen atoms, such as illustrated inFormula IIA, one of X¹ and X² may be an oxygen atom and the other may bea direct bond, such as shown in Formula IIB, or both X¹ and X² may bedirect bonds, such as illustrated in Formula IIC. The 1,1-disubstitutedalkene compounds used herein may have all ester groups (such asillustrated in Formula IIA), all keto groups (such as illustrated inFormula IIB) or a mixture thereof (such as illustrated in Formula IIC).Compounds with all ester groups are preferred due to the flexibility ofsynthesizing a variety of such compounds.

One or more as used herein means that at least one, or more than one, ofthe recited components may be used as disclosed. Nominal as used withrespect to functionality means the theoretical functionality, generallythis can be calculated from the stoichiometry of the ingredients used.Generally, the actual functionality is different due to imperfections inraw materials, incomplete conversion of the reactants and formation ofby-products. Durability in this context means that the composition oncecured remains sufficiently strong to perform its designed function, inthe embodiment wherein the cured composition is an adhesive, theadhesive holds substrates together for the life or most of the life ofthe structure containing the cured composition. As an indicator of thisdurability, the curable composition (e.g., adhesive) preferably exhibitsexcellent results during accelerated aging. Residual content of acomponent refers to the amount of the component present in free form orreacted with another material, such as a polymer. Typically, theresidual content of a component can be calculated from the ingredientsutilized to prepare the component or composition. Alternatively, it canbe determined utilizing known analytical techniques. Heteroatom meansnitrogen, oxygen, sulfur and phosphorus, more preferred heteroatomsinclude nitrogen and oxygen. Hydrocarbyl as used herein refers to agroup containing one or more carbon atom backbones and hydrogen atoms,which may optionally contain one or more heteroatoms. Where thehydrocarbyl group contains heteroatoms, the heteroatoms may form one ormore functional groups well known to one skilled in the art. Hydrocarbylgroups may contain cycloaliphatic, aliphatic, aromatic or anycombination of such segments. The aliphatic segments can be straight orbranched. The aliphatic and cycloaliphatic segments may include one ormore double and/or triple bonds. Included in hydrocarbyl groups arealkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, alkaryl andaralkyl groups. Cycloaliphatic groups may contain both cyclic portionsand noncyclic portions. Hydrocarbylene means a hydrocarbyl group or anyof the described subsets having more than one valence, such as alkylene,alkenylene, alkynylene, arylene, cycloalkylene, cycloalkenylene,alkarylene and aralkylene. One or both hydrocarbyl groups may consist ofone or more carbon atoms and one or more hydrogen atoms. As used hereinpercent by weight or parts by weight refer to, or are based on, theweight of the solution composition unless otherwise specified.

Unless defined otherwise, all technical and scientific terms used hereinhave the meaning commonly understood by a person skilled in the art towhich this disclosure belongs. The following references provide one ofskill with a general definition of many of the terms used in thisdisclosure: Singleton et al., Dictionary of Microbiology and MolecularBiology (2nd ed. 1994); The Cambridge Dictionary of Science andTechnology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R.Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, TheHarper Collins Dictionary of Biology (1991). As used herein, thefollowing terms have the meanings ascribed to them below, unlessspecified otherwise.

1,1-disubstituted alkene compound means a compound having a carbon witha double bond attached thereto and which is further bonded to two carbonatoms of carbonyl groups. A preferred class of 1,1-disubstituted alkenecompounds are the methylene malonates which refer to compounds havingthe core formula

The term “monofunctional” refers to 1,1-disubstituted alkene compoundsor a methylene malonates having only one core formula. The term“difunctional” refers to 1,1-disubstituted alkene compounds or amethylene malonates having two core formulas bound through a hydrocarbyllinkage between one oxygen atom on each of two core formulas. The term“multifunctional” refers to 1,1-disubstituted alkene compounds ormethylene malonates having more than one core formula which forms achain through a hydrocarbyl linkage between one oxygen atom on each oftwo adjacent core formulas. The term “latent acid-forming impurities” or“latent acid-forming impurity” refers to any impurity that, if presentalong with the 1,1-disubstituted alkene compounds or methylenemalonates, will with time be converted to an acid. The acid formed fromthese impurities may result in overstabilization of the1,1-disubstituted alkene compounds, thereby reducing the overall qualityand reactivity of the compounds. The term “ketal” refers to a moleculehaving a ketal functionality; i.e., a molecule containing a carbonbonded to two —OR groups, where O is oxygen and R represents any alkylgroup. The terms “volatile” and “non-volatile” refers to a compoundwhich is capable of evaporating readily at normal temperatures andpressures, in the case of volatile; or which is not capable ofevaporating readily at normal temperatures and pressures, in the case ofnon-volatile. As used herein, the term “stabilized” (e.g., in thecontext of “stabilized” 1,1-disubstituted alkene compounds or monomercompositions comprising same) refers to the tendency of the compounds(or the monomer compositions), prior to activation with an activator, tosubstantially not polymerize with time, to substantially not harden,form a gel, thicken, or otherwise increase in viscosity with time,and/or to substantially show minimal loss in cure speed (i.e., curespeed is maintained) with time. As used herein, the term “shelf-life”(e.g., as in the context of 1,1-disubstituted alkene compounds having animproved “shelf-life”) refers to the 1,1-disubstituted alkene compoundswhich are stabilized for a given period of time; e.g., 1 month, 6months, or even 1 year or more.

The hydrocarbyl groups (e.g., R¹ and R²), each comprise straight orbranched chain alkyl, straight or branched chain alkyl alkenyl, straightor branched chain alkynyl, cycloalkyl, alkyl substituted cycloalkyl,aryl, aralkyl, or alkaryl. The hydrocarbyl group may optionally includeone or more heteroatoms in the backbone of the hydrocarbyl group. Thehydrocarbyl group may be substituted with a substituent that does notnegatively impact the ultimate function of the monomer or the polymerprepared from the monomer. Preferred substituents include alkyl, halo,alkoxy, alkylthio, hydroxyl, nitro, cyano, azido, carboxy, acyloxy, andsulfonyl groups. More preferred substituents include alkyl, halo,alkoxy, alylthio, and hydroxyl groups. Most preferred substituentsinclude halo, alkyl, and alkoxy groups.

As used herein, alkaryl means an alkyl group with an aryl group bondedthereto. As used herein, aralkyl means an aryl group with an alkyl groupbonded thereto and include alkylene bridged aryl groups such as diphenylmethyl groups or diphenyl propyl groups. As used herein, an aryl groupmay include one or more aromatic rings. Cycloalkyl groups include groupscontaining one or more rings, optionally including bridged rings. Asused herein, alkyl substituted cycloalkyl means a cycloalkyl grouphaving one or more alkyl groups bonded to the cycloalkyl ring.

Preferred hydrocarbyl groups include 1 to 30 carbon atoms, morepreferably 1 to 20 carbon atoms, and most preferably 1 to 12 carbonatoms. Preferred hydrocarbyl groups with heteroatoms in the backbone arealkyl ethers having one or more alkyl ether groups or one or morealkylene oxy groups. Preferred alkyl ether groups are ethoxy, propoxy,and butoxy. Preferably such compounds contain from about 1 to about 100alkylene oxy groups and more preferably about 1 to about 40 alkylene oxygroups and more preferably from about 1 to about 12 alkylene oxy groups,and most preferably from about 1 to about 6 alkylene oxy groups.

One or more of the hydrocarbyl groups (e.g., R¹, R², or both),preferably includes a C₁₋₁₅ straight or branched chain alkyl, a C₁₋₁₅straight or branched chain alkenyl, a C₅₋₁₈ cycloalkyl, a C₆₋₂₄ alkylsubstituted cycloalkyl, a C₄₋₁₈ aryl, a C₄₋₂₀ aralkyl, or a C₄₋₂₀aralkyl. More preferably, the hydrocarbyl group, includes a C₁₋₈straight or branched chain alkyl, a C₅₋₁₂ cycloalkyl, a C₆₋₁₂ alkylsubstituted cycloalkyl, a C₄₋₁₈ aryl, a C₄₋₂₀ aralkyl, or a C₄₋₂₀aralkyl.

Preferred alkyl groups include methyl, propyl, isopropyl, butyl,tertiary butyl, hexyl, ethyl pentyl, and hexyl groups. More preferredalkyl groups include methyl and ethyl. Preferred cyclalkyl groupsinclude cyclohexyl and fenchyl. Preferred alkyl substituted groupsinclude menthyl and isobornyl.

Most preferred hydrocarbyl groups attached to the carbonyl group includemethyl, ethyl, propyl, isopropyl, butyl, tertiary, pentyl, hexyl, octyl,fenchyl, menthyl, and isobornyl.

Particularly preferred monomers include methyl propyl methylenemalonate, dihexyl methylene malonate, di-isopropyl methylene malonate,butyl methyl methylene malonate, ethoxyethyl ethyl methylene malonate,methoxyethyl methyl methylene malonate, hexyl methyl methylene malonate,dipentyl methylene malonate, ethyl pentyl methylene malonate, methylpentyl methylene malonate, ethyl ethylmethoxy methylene malonate,ethoxyethyl methyl methylene malonate, butyl ethyl methylene malonate,dibutyl methylene malonate, diethyl methylene malonate (DEMM), diethoxyethyl methylene malonate, dimethyl methylene malonate, di-N-propylmethylene malonate, ethyl hexyl methylene malonate, methyl fenchylmethylene malonate, ethyl fenchyl methylene malonate, 2 phenylpropylethyl methylene malonate, 3 phenylpropyl ethyl methylene malonate, anddimethoxy ethyl methylene malonate.

Some or all of the 1,1-disubstituted alkenes can also be multifunctionalhaving more than one core unit and thus more than one alkene group.Exemplary multifunctional 1,1-disubstituted alkenes are illustrated bythe formula:

wherein R¹, R² and X are as previously defined; n is an integer of 1 orgreater; and R is a hydrocarbyl group, and the 1,1-disubstituted alkenehas n+1 alkenes. Preferably n is 1 to about 7, and more preferably 1 toabout 3, and even more preferably 1. In exemplary embodiments R² is,separately in each occurrence, straight or branched chain alkyl,straight or branched chain alkenyl, straight or branched chain alkynyl,cycloalkyl, alkyl substituted cycloalkyl, aryl, aralkyl, or alkaryl,wherein the hydrocarbyl groups may contain one or more heteroatoms inthe backbone of the hydrocarbyl group and may be substituted with asubstituent that does not negatively impact the ultimate function of thecompounds or polymers prepared from the compounds. Exemplarysubstituents are those disclosed as useful with respect to R¹. Incertain embodiments R² is, separately in each occurrence, C₁₋₁₅ straightor branched chain alkyl, C₂₋₁₅ straight or branched chain alkenyl, C₅₋₁₈cycloalkyl, C₆₋₂₄ alkyl substituted cycloalkyl, C₄₋₁₈ aryl, C₄₋₂₀aralkyl or C₄₋₂₀ aralkyl groups. In certain embodiments R² is separatelyin each occurrence C₁₋₈ straight or branched chain alkyl, C₅₋₁₂cycloalkyl, C₆₋₁₂ alkyl substituted cycloalkyl, C₄₋₁₈ aryl, C₄₋₂₀aralkyl or C₄₋₂₀ alkaryl groups.

It will be appreciated according to the teaching herein, the one or moremonomer may include a comonomer that is a 1,1-disubstituted alkenecompound having a hydrocarbyl group bonded to each of the carbonylgroups through a direct bond (e.g., a carbon-carbon bond) or an oxygenatom, such as a monomer having one or more features described above. Ifincluded, a comonomer may optionally be a monomer that is not a1,1-disubstituted alkene compound. Any comonomer capable of anionicpolymerization may be employed. For example, the comonomer may becapable of forming a random copolymer with a 1,1-disubstituted alkenecompound, capable of forming a block copolymer with a 1,1-disubstitutedalkene compound, or both.

The 1,1-disubstituted alkene compound preferably is prepared using amethod which results in a sufficiently high purity so that it can bepolymerized. The purity of the 1,1-disubstituted alkene compound may besufficiently high so that 70 mole percent or more, preferably 80 molepercent or more, more preferably 90 mole percent or more, even morepreferably 95 mole percent or more, and most preferably 99 mole percentor more of the 1,1-disubstituted alkene compound is converted to polymerduring a polymerization process. The purity of the 1,1-disubstitutedalkene compound preferably is about 85 mole percent or more, morepreferably about 90 mole percent or more, even more preferably about 93mole percent or more, even more preferably about 95 mole percent ormore, even more preferably about 97 mole percent or more, and mostpreferably about 99 mole percent or more, based on the total weight ofthe 1,1-disubstituted alkene compound. If the 1,1-disubstitute alkenecompound includes impurities, preferably about 40 mole percent or more,more preferably about 50 mole percent or more of the impurity moleculesare the analogous 1,1-disubstited alkane compound. The concentration ofany impurities having a dioxane group preferably is about 2 mole percentor less, more preferably about 1 mole percent or less, even morepreferably about 0.2 mole percent or less, and most preferably about0.05 mole percent or less, based on the total weight of the1,1-disubstituted alkene compound. The total concentration of anyimpurity having the alkene group replaced by an analogous hydroxyalkylgroup (e.g., by a Michael addition of the alkene with water), preferablyis about 3 mole percent or less, more preferably about 1 mole percent orless, even more preferably about 0.1 mole percent or less, and mostpreferably about 0.01 mole percent or less, based on the total moles inthe 1,1-disubstituted alkene compound. Preferred 1,1-disubstitutedalkene compounds are prepared by a process including one or more (e.g.,two or more) steps of distilling a reaction product or an intermediatereaction product (e.g., a reaction product or intermediate reactionproduct of a source of formaldehyde and a malonic acid ester).

The 1,1-disubstituted alkene compound may include a monomer producedaccording to the teachings of U.S. Pat. No. 8,609,885 (Malofsky et al.)incorporated herein by reference in its entirety. Other examples ofmonomers which may be employed include the monomers taught inInternational Patent Application Publication Nos. WO2013/066629 and WO2013/059473, both incorporated herein by reference.

The concentration of the monomer in the solution polymerization processmay be sufficiently low so that after polymerization, the solution canflow. If the concentration of the monomer is too high, the solutionbecomes too viscous at the end of the polymerization process and thesolution may be difficult to handle. The concentration of the monomer inthe solution polymerization process may be sufficiently high so that thepolymerization process is economical. The one or more monomers ispreferably present at a concentration of about 0.5 weight percent ormore, more preferably about 2 weight percent or more, even morepreferably about 5 weight percent or more, and most preferably about 8weight percent or more, based on the total weight of the solvent andmonomer. The one or more monomers may be present at a concentration ofabout 90 weight percent or less, preferably about 75 weight percent orless, more preferably about 50 weight percent or less, even morepreferably about 30 weight percent or less, and most preferably about 20weight percent or less. If the monomer is added at multiple times (suchas continuous and/or sequential monomer addition), it will beappreciated that the amount of the one or more monomers refers to thetotal amount of monomer and polymer and by-products of the monomer thatare present when the addition of monomer has been completed.

Solvent

The polymerization process includes one or more solvents selected sothat the monomer and solvent form a single phase. Preferably the solventdoes not chemically react with the other components of the solutionpolymerization system during the polymerization process. For example,the solvent preferably does not react with the monomer. As anotherexample, the solvent preferably does not react with the activator. Assuch, the amount of the solvent present at the end of the polymerizationreaction may be substantially the same as the amount of solvent presentat the start of the polymerization reaction. For example the change inthe amount of solvent may be about 20% or less, preferably about 10% orless, more preferably about 5% or less, even more preferably about 1% orless, and most preferably about 0.2% or less, based on the initialweight of the solvent at the start of the polymerization process.

Preferred solvents are organic solvents, or mixtures of organicsolvents. Such solvents, or solvent mixtures typically are in a liquidstate at the reaction temperature(s) (e.g., during activation and/orduring polymerization.

The pressure of the solvent (e.g., organic solvent) and of the monomerat the polymerization temperature should be sufficiently low so that therisk of the reactor failing from over-pressure is reduced or eliminated.For example the partial pressure of the solvent, of the monomer, orboth, at the polymerization temperature may be about 500 Torr or less,about 200 Torr or less, about 50 Torr or less, or about 5 Torr or less.

The solvent may include one or more protic solvents, one or more aproticsolvents, or both. Preferably the solvent includes, consists essentiallyof, or consists entirely of one or more aprotic solvent. An aproticsolvent may include one or more polar aprotic solvent and/or one or morenonpolar aprotic solvents. Preferred aprotic solvents include, consistessentially of, or consist entirely of one or more polar aproticsolvents. Most preferably, the solvent is substantially free of (e.g.,having a concentration of less than about 10 weight percent, less thanabout 5 weight percent, or less than 1 weight percent of the solvent)protic solvents and/or nonpolar aprotic solvents. Examples of solventswhich may be employed include alkanes, aryl containing compounds,alcohols, acetates, hydrofurans, ketones, halocarbon containingcompounds, and mixtures thereof. More preferred solvents includeacetates, hydrofurans, ketones, halocarbon containing compounds, andmixtures thereof. Preferred solvents are compounds having a molecularweight of about 200 g/mole or less, more preferably about 120 g/mole orless, and most preferably about 80 g/mole or less. Particularlypreferred solvents include tetrahydrofuran, n-propyl acetate, benzene,and xylene.

It may be desirable for the solvent to be substantially or entirely freeof any solvent that may react with the monomer via Michael addition.However, by selecting reaction conditions so that the polymerizationreaction is sufficiently fast, it may be possible to employ suchmonomers in the solvent polymerization process. For example, byselecting parameters such as monomer feed rates, reaction temperature,monomer type, and pH, it may be possible to employ a solvent includingor consisting of a protic solvent, such as an alcohol.

The solvent may be selected to be generally compatible or miscible withone or more of the monomers (e.g., with the primary monomer), with thepolymer (e.g., with one or more blocks of a block copolymer), or both.For example, the solvent and the monomer may be characterized byHildebrand solubility parameters that differ by about 5 (MPa)^(1/2) orless, more preferably that differ by about 2 (MPa)^(1/2) or less, evenmore preferably that differ by about 1 (MPa)^(1/2) or less, even morepreferably that differ by about 0.7 (MPa)^(1/2) or less, and mostpreferably that differ by about 0.4 (MPa)^(1/2) or less. The solvent andmonomer may have about the same Hildebrand solubility parameter. In someaspects, it may be desirable for the polymer to remain in solution untilafter polymerization is complete. In other aspects, it may be desirablefor the polymer to precipitate out (e.g., by forming a phase that isrich in the polymer, that consists essentially of the polymer, or thatconsists entirely of the polymer) during the polymerization process.

If the concentration of solvent is too low, the solution becomes tooviscous at the end of the polymerization process and the solution may bedifficult to handle. The solvent may be present at a concentration ofabout 10 weight percent or more, preferably about 25 weight percent ormore, more preferably about 35 weight percent or more, even morepreferably about 45 weight percent or more, even most preferably about50 weight percent or more, based on the total weight of the solvent andmonomer. In cases where increased control is critical, the concentrationof the solvent may be about 60 weight percent or more, or about 85weight percent or more, based on the total weight of the solvent andmonomer. The solvent is preferably present at a concentration of about99.5 weight percent or less, more preferably about 98 weight percent orless, even more preferably about 95 weight percent or less, and mostpreferably about 92 weight percent or less, based on the total weight ofthe solvent and monomer.

It may be desirable for the polymer to be isolated from some or all ofthe solvent. As such, it may be advantageous to select a solvent thatforms a single phase with the monomer, but after polymerizing themonomer to a desired molecular weight (e.g., number average molecularweight) the polymer will precipitate out of solution. Alternatively,after the completion of polymerization, a compound that is a poorsolvent to the polymer may be added to the solution to cause the polymerto precipitate out, such as described herein.

The solution polymerization may be initiated using an activator capableof initiating anionic polymerization of the 1,1-disubstituted alkenecontaining compound. The activator may be a compound that is anucleophile or a compound that forms a nucleophile. Examples ofactivators (i.e., initiators), which may be employed, include ionicmetal amides, hydroxides, cyanides, phosphines, alkoxides, amines andorganometallic compounds (such as alkyllithium compounds), and metalbenzoates. The polymerization activator may have one or more of thefeatures (e.g., include one or any combinations of the activating agentsand/or polymerization activators, include an activating agent at aconcentration or concentration range, or include a process step) asdescribed in US patent Application publication US 2015/0073110 A1,published on Mar. 12, 2015, incorporated herein by reference (e.g., seeparagraphs 0024 to 0050). By way of example, the activator may include,consist essentially of, or consist entirely of one or more metalbenzoates, such as sodium benzoate. The molecular weight of the polymermay be adjusted by adjusting the molar ratio of the monomer to theactivator. Preferably the molar ratio of the monomer to activator isabout 5 or more, about 50 or more, about 100 or more, about 500 or more,or about 1,000 or more. The molar ratio of the monomer to the activatorpreferably is about 100,000 or less, about 50,000 or less, about 10,000or less, or about 2,000 or less. A particularly preferred activator forthe anionic polymerization process according to the teachings herein issec-butyl lithium. Sec-buyl lithium may be employed in activating thepolymerization of a homopolymer or of a copolymer (e.g., a randomcopolymer, or a block copolymer).

According to certain embodiments, a suitable polymerization activatorcan generally be selected from any agent that can initiatepolymerization substantially upon contact with a selected polymerizablecomposition. In certain embodiments, it can be advantageous to selectpolymerization initiators that can induce polymerization under ambientconditions and without requiring external energy from heat or radiation.In embodiments wherein the polymerizable composition comprises one ormore 1,1-disubstituted alkene compounds, a wide variety ofpolymerization initiators can be suitable including most nucleophilicinitiators capable of initiating anionic polymerization. For example,suitable initiators include alkali metal salts, alkaline earth metalsalts, ammonium salts, amine salts, halides (halogen containing salts),metal oxides, and mixtures containing such salts or oxides. Exemplaryanions for such salts include anions based on halogens, acetates,benzoates, sulfur, carbonates, silicates and the like. The mixturescontaining such salts can be naturally occurring or synthetic. Specificexamples of suitable polymerization initiators for 1,1-disubstitutedalkene compounds can include ionic compounds such as sodium benzoate,sodium pyruvate, and tetramethyl guanidine. Additional suitablepolymerization initiators for such polymerizable compositions are alsodisclosed in U.S. Patent Application Publication No. 2015/0073110, whichis hereby incorporated by reference.

The solvent and/or one or more of the monomers (e.g., the1,1-disubstituted alkene compounds) may further contain other componentsto stabilize the monomer prior to exposure to polymerization conditionsor to adjust the properties of the final polymer for the desired use.Prior to the polymerization reaction, one or more inhibitors may beadded to reduce or prevent reaction of the monomer. Such inhibitors maybe effective in preventing anionic polymerization of the monomer, freeradical polymerization of the monomer, reaction between the monomer andother molecules (such as water), or any combination thereof.

An acid containing compound may be employed in the solutionpolymerization process. With various monomers, the use of an acidcontaining compound may be employed to reduce the reaction rate,decrease the polydispersity, or both. When the concentration of the acidcontaining compound is too high, the polymerization reaction may be tooslow for commercial viability. When the concentration of the acidcontaining compound is too low, the polymerization reaction may resultin a polymer having rapid and/or uncontrolled buildup of molecularweight. The acid containing compound may be an organic compound havingone or more acid groups. For example, the acid containing compound mayinclude one or more acid groups having a sulfur, phosphorous, chlorine,or bromine, fluorine or nitrogen atom. The acid containing compoundpreferably includes one or more nitrogen atoms (such as in a nitrate ornitrite group) and/or one or more sulfur atoms (such as an alkyl or arylsulfonic acid. Particularly preferred acid containing compounds includemethanesulfonic acid and benzoic acid. It will be appreciated that theacid containing compounds may affect the initiation, propagation, ortermination of the polymer. The weight ratio of the acid containingcompound to the amount of the monomer employed for a polymerization step(e.g., for polymerizing a first polymer block) preferably is about0.00005 or more, more preferably about 0.0002 or more and mostpreferably about 0.0005 or more. The weight ratio of the acid containingcompound to the amount of the monomer employed for a polymerization step(e.g., for polymerizing a first polymer block) preferably is about 0.2or less, more preferably about 0.04 or less, and most preferably about0.005 or less.

The polymerization process may include a step of applying shear forcesto a mixture including at least the monomer and the solvent. Forexample, the process may include stirring or otherwise agitating themixture for creating the solution, for dispersing or removing aprecipitated polymer, for controlling thermal gradients, or anycombination thereof.

The polymerization process may be a batch process (e.g., using a singlebatch reactor or a series of batch reactors). The polymerization processmay be in a continuous process, such as a process that transports asolution along the length of a reactor. In a batch process, or in acontinuous process, all of the monomer may be added at a single stage(e.g., prior to the addition of the polymerization activator, or at ornear the start of the polymerization reaction) or may be added atmultiple stages in the polymerization reaction.

The polymerization process may be employed for polymerization of ahomopolymer or a copolymer, such as a random copolymer or a blockcopolymer. The homopolymer or copolymer includes one or more1,1-disubstituted alkene containing compounds according to the teachingsherein. Preferably, the amount of the 1,1-disubstituted alkenecontaining compounds in the polymer is about 5 weight percent or more,more preferably about 30 weight percent or more, even more preferablyabout 50 weight percent or more, even more preferably about 70 weightpercent or more, based on the total weight of the polymer. For example,one or more of the polymer blocks may consist essentially of, orentirely of the 1,1-disubstituted alkene containing compounds.

A multi-stage addition of monomer may be employed for polymerization ofa block copolymer having polymer blocks with different compositions. Forexample, a block copolymer may have a first polymer block, (block A),and a second polymer block (block B). The block copolymer may have 2 ormore blocks or 3 or more blocks. The A block and B block may include atleast one monomer that is the same (however at differentconcentrations), or may include only monomers that are different. Forexample, the A block may be a homopolymer of a first monomer, and the Bblock may include one or more second monomers which are each differentfrom the first monomer. The first polymer block may be a homopolymer ora copolymer (e.g., a random copolymer). The second polymer block may bea homopolymer or a copolymer (e.g., a random copolymer). The firstpolymer block and the second polymer block preferably each include oneor more 1,1-disubstituted alkene containing compounds according to theteachings herein. Preferably, the amount of the 1,1-disubstituted alkenecontaining compounds in the first polymer block and/or in the secondpolymer block may be about 30 weight percent or more, preferably about50 weight percent or more, even more preferably about 70 weight percentor more, based on the total weight of the polymer block. For example,one or more of the polymer blocks may consist essentially of, orentirely of the 1,1-disubstituted alkene containing compounds. It willbe appreciated that one or more blocks may be substantially or entirelyfree of any 1,1-disubstituted alkene containing compounds. For example,one or more of the polymer blocks may include one or more conjugateddiene monomers and/or one or more styrenic monomers.

During the polymerization process, the solution is preferably stirred orotherwise agitated to create the solution. For example, the solutionincluding the monomer, the solvent, and any polymer may be mixed at arate of about 10 rpm or more, about 50 rpm or more, about 200 rpm ormore, or about 1,000 rpm or more.

The solution polymerization process preferably includes a reactiontemperature at which the partial pressure of the solvent is generallylow. For example, the partial pressure of the solvent and/or the monomermay be about 400 Torr or less, about 200 Torr or less, about 100 Torr orless, about 55 Torr or less, or about 10 Torr or less. The reactiontemperature preferably is about 80° C. or less, more preferably about70° C. or less, even more preferably about 60° C. or less, even morepreferably about 55° C. or less, even more preferably about 45° C. orless, even more preferably about 40° C. or less, and most preferablyabout 30° C. or less. The reaction temperature typically is sufficientlyhigh that the solvent and the monomer are in a liquid state. Forexample, the reaction temperature may be about −100° C. or more, about−80° C. or more, about −30° C. or more, or about 10° C. or more.

When polymerizing a 1,1-disubstituted alkene compound, it may bedesirable to add one or more acid compounds to the solution, to themonomer, or both, so that the initial pH of the solution is about 7 orless, about 6.8 or less, about 6.6 or less, or about 6.4 or less. It isbelieved that such an initial acidic condition may be beneficial forcontrolling or otherwise limiting the initiation of the monomer. Forexample, the 1,1-disubstituted alkene compound may be a compound thatwill auto-initiate under basic conditions and the use of an acidcondition may prevent or minimize such auto-initiation. The acidiccondition preferably is maintained throughout the polymerizationprocess. If the pH is too low, the reaction rate may be low or thereaction may be terminated. Preferably, the pH during the reaction isabout 5 or more, more preferably about 5.5 or more, even more preferablyabout 5.9 or more, and most preferably about 6 or more. It will beappreciated that following the polymerization process the pH may beadjusted to increase or decrease the pH.

The solution polymerization process may be stopped prior to thecompletion of the polymerization reaction or may be continued until thecompletion of the polymerization reaction. Preferably, the reaction rateis sufficiently high and/or the reaction time is sufficiently long sothat the polymerization reaction is substantially complete. For examplethe conversion of the monomer to polymer may be about 30 weight percentor more, about 60 weight percent or more, about 90 weight percent ormore, about 95 weight percent or more, or about 99 weight percent ormore. The conversion of monomer to polymer may be about 100 weightpercent or less.

With reference to FIG. 2, the solution polymerization process 30typically includes a step of developing a generally homogenous solution.For example, the process may include a step of combining a solvent, oneor more monomers, and an activator. It will be appreciated that thecomponents of the solution may be added at one time, may be added atdifferent times, or some components may be combined separately. Thedevelopment of the homogeneous solution 32 typically requires agitation.Depending on the type and intensity of the agitation, it may be possibleto control the rate at which the homogenous solution is developed. Theprocess typically includes a step of initiating the polymerizationreaction 34. The initiation step preferably occurs after the monomer andsolvent have been homogenized. It will be appreciated that an activatormay be added into the system prior to the addition of monomer, at thesame time as the addition of the monomer, or after addition of a firstportion of the monomer and prior to the addition of a second portion ofthe monomer. After activation of the monomer, the process includes astep of propagating the polymer by an anionic polymerization reaction36. The propagating step may continue until all of the monomer isconsumed, or until the propagation reaction is stopped, such as byquenching 38 or the conditions are altered so that further anionicpolymerization reaction stops. The propagation step may also stop by aphase separation of the polymer from the monomer (e.g., where themonomer has difficulty in contacting the reactive end of the polymermolecule). Prior to a step of quenching, there may be one or moreadditional steps of feed monomer (which may be the same or differentfrom the initial monomer feed), and one or more additional steps ofpropagating the polymerization reaction. With each such propagatingstep, the polymer molecular weight generally increases, unlessconditions for addition chain activation are provided (for example byadding additional activator). It will be appreciated that the resultingpolymer may be capable of further reaction with monomer and may thus bea “living” polymer.

The conversion of monomer to polymer may be measured using NMRspectroscopy, such as illustrated in FIG. 3A and FIG. 3B, correspondingto an early and a later stage of a propagation reaction for polymerizinga 1,1-disubstituted alkene monomer. Here, the monomer is diethylmethylene malonate and the concentration of the monomer can be monitoredby the peak at about 6.45 ppm 40 corresponding to the reactive doublebond of the monomer. Hexamethyldisiloxane is used here an internalstandard (i.e., internal reference) 42 and is seen at about 0 ppm. Itwill be appreciated that other compounds may be employed as an internalstandard. In FIG. 3A, the NMR spectrogram was measured on a firstaliquot taken from a specimen initiated with sodium benzoate at a molarratio of monomer to initiator of about 100:1. The first aliquot wastaken after the reaction had propagated for about 30 seconds at roomtemperature. The first aliquot was quenched with an acid to stop thepropagation reaction. FIG. 3B shows the NMR spectrogram from a secondaliquot taken from the same specimen after about 5 minutes of thepropagation reaction. As seen in FIG. 3B, the monomer is no longerdetectable as evidenced by a lack of the reactive double bond peak atabout 6.45 ppm 40.

The polymers according to the teachings herein preferably have a numberaverage molecular weight or a weight average molecular weight that isabout 700 g/mole or more, more preferably about 2,000 g/mole or more,even more preferably about 10,000 g/mole or more, and most preferablyabout 20,000 g/mole or more. The molecular weight of the polymer may besufficiently low so that the polymer may be easily processed. The numberaverage molecular weight or the weight average molecular weightpreferably is about 3,000,000 g/mole or less, more preferably about2,000,000 g/mole or less, even more preferably about 1,000,000 g/mole orless, and most preferably about 600,000 g/mole or less.

The resulting polymer may be a relatively low molecular weight polymerhaving a number average molecular weight of about 40,000 g/mole or less,about 30,000 g/mole or less, or about 20,000 g/mole or less. Theresulting polymer may be a relatively high molecular weight polymerhaving a number average molecular weight of greater than 40,000 g/mole,about 60,000 g/mole or more, or about 100,000 g/mole or more.

The resulting polymer may be characterized by a polydispersity index ofabout 1.00 or more or about 1.05 or more. The resulting polymer may becharacterized by a polydispersity index of about 20 or less, preferablyabout 7 or less, more preferably about 4 or less, and most preferablyabout 2.3 or less. The resulting polymer may have a narrow molecularweight distribution such that the polydispersity index is about 1.9 orless, about 1.7 or less, about 1.5 or less, or about 1.3 or less.

The degree of polymerization, as used herein, is generally the molecular(as defined herein) divided by the average molecular weight of themonomer units. For example, the weight average degree of polymerizationof a homopolymer is the weight average molecular weight of thehomopolymer (e.g., in units based on the PMMA standards) divided by themolecular weight of the monomer unit.

Surprisingly, by employing an acid containing compound according to theteachings herein, it may be possible to reduce the polydispersity of apolymer (e.g., of a polymer block) without a substantive reduction inthe polymerization reaction rate. For example, the polydispersity of theratio of the polymer prepared with the acid containing compound to thepolydispersity of a polymer prepared using the same method exceptwithout the use of the acid containing compound may be about 0.9 orless, about 0.8 or less, about 0.7 or less, or about 0.6 or less. Theratio of the time for converting 80% of the monomer to polymer for theprocess including the acid containing compound to the time forconverting 80% of the monomer to polymer in the identical process(except without the acid containing compound) preferably is about 5 orless, more preferably about 3 or less, even more preferably about 2 orless, and most preferably about 1.5 or less.

The molecular weight of the polymer may be measured using gel permeationchromatography (i.e., GPC), FIG. 5A of U.S. Pat. No. 9,279,022,illustrates a GPC curve for a homopolymer prepared by polymerizingdiethyl methylene malonate in an solution system. TMG is used as theactivator for the anionic polymerization of the monomer. The molar ratioof monomer to the activator is about 1000:1. The reaction was continueduntil about 100 percent of the monomer was converted to polymer. The GPCcurve 58 of the resulting homopolymer is shown in FIG. 5A of U.S. Pat.No. 9,279,022. This sample has a single peak which defines an area 50for calculating the molecular weight characteristics of the polymer(e.g., weight average molecular weight, peak molecular weight, numberaverage molecular weight, z-average molecular weight, andpolydispsersity index). The GPC curve 58 shows the signal intensity(which correlates with concentration) as a function of the retentiontime in minutes. The calibration curve 54 is also shown in FIG. 5A ofU.S. Pat. No. 9,279,022. The calibration curve shows the retention timefor a series of PMMA standards of known molecular weight. The low limit56 for measuring the molecular weight based on these standards is about200 daltons. The sequential increase in the molecular weight of a blockcopolymer after the addition of each of four polymer blocks is shown inFIGS. 5A, 5B, 5C, and 5D of U.S. Pat. No. 9,279,022.

The solution polymer according to the teachings herein may becharacterized as an elastomer. For example, the resulting polymer may besubstantially free of a melting temperature and substantially free of aglass transition temperature of about 15° C. or more.

The solution polymer according to the teaching herein may becharacterized as a thermoplastic having a melting temperature and/or aglass transition temperature of about 15° C. or more, about 50° C. ormore, about 80° C. or more, about 100° C. or more, or about 120° C. ormore. Polymers having a high glass transition temperature include thosehaving hydrocarbonyl groups that provide steric hindrance that reducethe mobility of polymer molecules in the melt state. The meltingtemperature and/or the glass transition temperature of the thermoplasticmay be about 300° C. or less, about 250° C. or less, or about 150° C. orless.

The solution polymer according to the teachings herein may becharacterized as a block copolymer including at least one block having aglass transition temperature or melting temperature of about 15° C. ormore (e.g., about 50° C. or more, about 80° C. or more, or about 100° C.or more) and at least one different block having no melting temperatureabove 15° C. and having a glass transition temperature of less than 15°C. (e.g., about 10° C. or less, about 0° C. or less, or about −20° C. orless). In one aspect, a block copolymer may be prepared with blocks thatare not miscible so that the resulting block copolymer has multiplephases at room temperature. As such, the block copolymer may have afirst glass transition temperature corresponding to the first polymerblock and a second glass transition temperature corresponding to thesecond polymer block. It will be appreciated that the glass transitiontemperature of the blocks may be tailored based on the monomer ormonomers used in the particular block and/or based on end effects (whichincludes the effect of the number of monomer units in the block). Forpurposes of illustration, a polymer block consisting essentially of, orconsisting entirely of: (1) diethyl methylene malonate homopolymer isexpected to have a glass transition temperature of about 25° C. to about45° C. (preferably about 30° C.), (2) fenchyl methyl methylene malonateis expected to have a glass transition temperature of about 125° C. toabout 200° C. (preferably about 150° C.), (3) methyl methoxyethylmethylene malonate is expected to have a glass transition temperature ofabout −15° C. to about +10° C. (preferably about 0° C.), (4) hexylmethyl methylene malonate is expected to have a glass transitiontemperature of about −45° C. to about 0° C. (preferably about −34° C.),(5) dibutyl methylene malonate is expected to have a glass transitiontemperature of about −55° C. to about −35° C. (preferably about −44°C.). It may be possible to prepare a block copolymer having multipleglass transition temperatures, such as a first glass transitiontemperature characteristic of a first polymer block and a second glasstransition temperature characteristic of a second polymer block. In someblock copolymers, a single glass transition is observed indicating thata single phase is formed, indicating that the two polymer blocks havesubstantially the same glass transition temperature (e.g., a differenceof about 20° C. or less, about 10° C. or less, or both).

The solution polymer according to the teachings herein may be acharacterized as a random copolymer and/or having a polymer block thatis a random copolymer. The random copolymer may include a primarymonomer (e.g., present at a concentration of about 50 mole percent ormore) and a secondary monomer randomly distributed through the polymerchain and having a concentration of less than 50 mole percent. Theproperties of the random copolymer will generally differ from theproperties of a homopolymer consisting entirely of the primary monomer.For example, as the amount of the secondary monomer is increased fromabout 0.5 mole percent to about 49.5 mole percent, the glass transitiontemperature of the random copolymer may shift from a glass transitiontemperature characteristic of the primary monomer towards a glasstransition temperature characteristic of the secondary monomer. Whenprepared as a random copolymer, the polymer typically has a single glasstransition temperature (e.g., even when a mixture of a homopolymer ofthe primary monomer and a homopolymer of the secondary monomer, at thesame concentration, exhibits multiple glass transition temperatures). Ahomopolymer may have a single glass transition temperature, such asillustrated in FIG. 4A for a homopolymer of 2-phenyl-1-propanol ethylmethylene malonate (Tg of about 59.4° C.) and FIG. 4B for a homopolymerof fenchyl methyl methylene malonate (Tg of about 146.9° C.). A randomcopolymer (of monomer A and monomer B) may have one or more glasstransition temperatures between the glass transitions of thecorresponding homopolymer (homopolymer A and homopolymer B), such asillustrated in FIG. 4C, a random copolymer of 2-phenyl-1-propanol ethylmethylene malonate (about 50 weight percent) and fenchyl methylmethylene malonate (about 50 weight percent) having a glass transitiontemperature of about 86.3° C. Preferably, the glass transitiontemperature of the random copolymer of monomer A and monomer B, maydiffer from the glass transition temperature of both homopolymer A andhomopolymer B (e.g., all having a weight average molecular weight ofabout 10,000 or more, or about 40,000 or more) by about 10° C. or more,by about 20° C. or more, or by about 25° C. or more.

The homopolymer of the primary monomer may be a semicrystalline polymer.Typically, when a secondary monomer is added in preparing a randomcopolymer, the secondary monomer will partially inhibit the ability ofthe primary monomer to crystallize, resulting in a random copolymerhaving different properties from the homopolymer such as a lowercrystallinity, a lower flexural modulus, a lower melting temperature, orany combination thereof. For example, the selection of the secondarymonomer and/or the amount of the secondary monomer in the randomcopolymer may be selected so that the random copolymer has a meltingtemperature that is reduced (i.e., relative to the homopolymer of theprimary monomer) by about 5° C. or more, by about 10° C. or more, byabout 15° C. or more, or by about 20° C. or more. The selection of thesecondary monomer and/or the amount of the secondary monomer in therandom copolymer may be selected so that the random copolymer has acrystallintity that is reduced (i.e., relative to the homopolymer of theprimary monomer) by about 10% or more, by about 20% or more, by 40% ormore, or by about 60% or more.

The resulting polymer may be a block copolymer including at least afirst polymer block and a second polymer block different from the firstpolymer block. The first polymer block and the second polymer block maydiffer with respect to one or any combination of the followingproperties: peak melting temperature, final melting temperature,crystallinity, glass transition temperature, flexural modulus, tensilemodulus, elongation at failure, gas barrier properties, or adhesionproperties. For example, the first polymer block and the second polymerblock may have melting temperatures (peak melting temperatures and/orfinal melting temperatures) differing by about 10° C. or more, about 20°C. or more, about 30° C. or more, or about 50° C. or more. It will beappreciated that one polymer block may have a melting temperature andthe other polymer block may be free of crystalline polymer so that thereis no measurable melting temperature. The first polymer block and thesecond polymer block may have glass transition temperatures differing byabout 10° C. or more, about 20° C. or more, about 30° C. or more, orabout 40° C. or more. The first polymer block and the second polymerblock may have crystallinities that differ by about 10% or more, about15% or more, about 20% or more, about 25% or more, or about 30% or more.The first polymer block and the second polymer block may have moduli(e.g., flex modulus, tensile modulus, or both) having a ratio of about1.5 or more, about 2 or more, about 4 or more, about 8 or more, or about15 or more. The first polymer block and the second polymer block mayhave a ratio of elongation at failure and/or a ratio of tensile strengthof about 2 or more, about 3 or more, about 4 or more, or about 6 ormore.

The degree of blockiness (i.e, the blockiness index, or BI) in a randomcopolymer may be calculated by the ratio of the concentration of diadfractions of a first monomer (e.g., a primary monomer that is a1,1-disubstituted alkene compound) added to the second monomer f(M1−M2)plus the diad fractions of the second monomer added to the first monomerf(M2−M1) to the theoretical concentration of diad fractions for astatistical random copolymer 2 X_(M1) (1−X_(M1)), where X_(M1) is themolar fraction of first monomer:BI=(f(M1−M2)+f(M2−M1))/(2X _(M1)(1-X ^(M2)))By definition a true statistically random copolymer has a BI of one(1.0). Blocky random copolymers will have a lower concentration of M1−M2and M2−M1 diad fractions, and BI will be less than 1.0. Block copolymerswill have very low concentrations of M1−M2 and M2−M1 diad fractions andBI will be much less than 1 and approach zero. On the other end,alternating copolymers having X_(M1)≥0.5 will have BI=1+(1/X_(M1)). Theconcentration of the diad fractions and X_(M1) may be measured using ¹³CNMR spectroscopy, using analogous peak assignments and techniquesdescribed by Yi-Jun Huange et al. in “Random Copolymers of PropyleneOxide and Ethylene Oxide Prepared by Double Metal Cyanide ComplexCatalyst”, Chinese Journal of Polymer Science, 20:5, 2002, pages453-459, incorporated herein by reference in its entirety.

Preferred random copolymers have a BI of about 0.70 or more, morepreferably about 0.75 or more, even more preferably about 0.80 or more,even more preferably about 0.85 or more, even more preferably about 0.90or more, and most preferably about 0.95 or more. Preferred randomcopolymers have a BI preferably less than about 1+(0.8/x_(M1)), morepreferably less than about 1+(0.5/x_(M1)), even more preferably lessthan about 1+(0.25/x_(M1)), and most preferably less than about1+(0.10/x_(M1)) where x_(M1) is the molar fraction of primary monomer inthe copolymer and x_(M1) is at least 0.5.

The resulting polymer may be employed in a polymeric compositionincluding one or more additives, such as antioxidants, heat stabilizers,light stabilizers, process stabilizers, lubricants, antiblocking agents,antistatic agent, anti-fogging agents, solvents, plasticizers, fillers,antistatic agents, coupling agents (e.g., for the fillers), crosslinkingagents, nucleating agent, anti-blocking agent, defoaming agents,pigments, colorant, flame retardant additives, flow aid, lubricant, slipagent and other processing aids known to the polymer compounding art.Suitable flame retardants may include halogen containing flameretardants and halogen free flame retardants.

Polymeric compositions may comprise one or more other fillers, such as afiller particle (e.g., fibers, powders, beads, flakes, granules, and thelike). The filler particle may be a fiber (e.g., having an aspect ratioof the longest direction to each perpendicular direction that is greaterthan 10). The filler particle may be a particle that is not a fiber(e.g., having an aspect ratio of the longest direction to aperpendicular direction that is less than 10, less than 8, or less than5). The filler may be formed of an organic material and/or an inorganicmaterial. Examples of organic fillers include fillers derived frombiomass and fillers derived from polymers. Inorganic fillers include,nonmetallic materials, metallic materials, and semiconductor material.For example, the filler particle may include alumina silicate, aluminumhydroxide, alumina, silicon oxide, barium sulfate, bentonite, boronnitride, calcium carbonate (e.g., activated calcium carbonate, lightcalcium carbonate, or heavy calcium carbonate), calcium hydroxide,calcium silicate, calcium sulfate, carbon black, clay, cotton flock,cork powder, diatomaceous earth, dolomite, ebonite powder, glass,graphite, hydrotalcite, iron oxide, iron metallic particles, kaolin,mica, magnesium carbonate, magnesium hydroxide, magnesium oxide,phosphide, pumice, pyrophyllite, sericite, silica, silicon carbide,talc, titanium oxide, wollastonite, zeolite, zirconium oxide, or anycombination thereof. The filler particles may be present at aconcentration of about 0.1 weight percent or more, about 1 weightpercent or more, about 5 weight percent or more, or about 10 weighpercent or more. The filler particles may be present at a concentrationof about 70 weight percent or less, about 50 weight percent or less,about 35 weight percent or less, or about 25 weigh percent or less. Thefiller particles preferably have one, two, or three dimensions that areabout 1 mm or less, about 0.3 mm or less, about 0.1 mm, about 50 μm orless, about 10 μm or less. The filler particles preferably have one,two, or three dimensions that are about 0.1 μm or more, about 0.3 μm ormore, or about 1 μm or more.

The polymeric compositions according to the teachings herein may includea plasticizer for adjusting the properties of the final polymer for thedesired use. The plasticizer may be added prior to, during, or afterpolymerization. For example, in certain embodiments, a suitableplasticizer can be included with the 1,1-disubstituted alkene monomer.Generally, suitable plasticizers can include plasticizers used to modifythe rheological properties of adhesive systems including, for example,straight and branched chain alkyl-phthalates such as diisononylphthalate, dioctyl phthalate, and dibutyl phthalate, as well aspartially hydrogenated terpene, trioctyl phosphate, epoxy plasticizers,toluene-sulfamide, chloroparaffins, adipic acid esters, sebacates suchas dimethyl sebacate, castor oil, xylene, 1-methyl-2-pyrrolidione andtoluene. Commercial plasticizers such as HB-40 manufactured by SolutiaInc. (St. Louis, Mo.) can also be suitable.

The process may include one or more steps of monitoring or otherwisemeasuring the conversion rate of the monomer to polymer. Theconcentration of the remaining monomer may be determined for exampleusing NMR spectroscopy. For example, quantitative NMR spectroscopy maybe employed to measure the concentration of alkylene groups (e.g.,1-ethylene groups) remaining in the solution.

The solution polymer of the current teaching may be mixed with one ormore additional polymers for preparing a polymeric composition. Theconcentration of the solution polymer in the polymeric composition maybe about 1 weight percent or more, about 5 weight percent or more, about10 weight percent or more, about 20 weight percent or more, or about 50weight percent or more, based on the total weight of the polymers in thepolymeric composition. The solution polymer may be present in thepolymeric composition at a concentration of about 100 weight percent orless, about 95 weight percent or less, or about 90 weight percent orless, or about 60 weight percent or less, based on the total weight ofthe polymers in the polymeric composition.

The process may include one or more steps of removing some or all of thesolvent from the polymer. The process of removing the solvent may useheat, reduced pressure or both for separating the polymer from thesolvent. The process of removing the solvent may include a step offiltering and/or a step of adding one or more additional liquids to thesolution. For example, a non-solvent may be added at a sufficientquantity to precipitate polymer out of solution. As another example, asolvent may be added to increase the solubility of the solvent mixtureand retain the polymer in the solvent solution. Other liquids may beemployed for washing a precipitate, such as after a step of filtering.The process may include one or more steps of recovering unreactedmonomer following polymerization. The process may include one or moresteps of purifying a solvent (e.g., following polymerization and/or foruse in polymerization).

The process may include one or more steps of terminating (i.e.,quenching) the anionic polymerization reaction. For example,polymerization can be quenched by contacting the solution with ananionic polymerization terminator. In some embodiments the anionicpolymerization terminator is an acid. In some embodiments it isdesirable to utilize a sufficient amount of the acid to render thepolymerization mixture (e.g., the solution and/or the solvent) slightlyacidic, preferably having a pH of less than 7, more preferably less than6. Exemplary anionic polymerization terminators include, for example,mineral acids such as methanesulfonic acid, sulfuric acid, andphosphoric acid and carboxylic acids such as acetic acid andtrifluoroacetic acid.

The polymers and polymer compositions according to the teachings herein(e.g., after removing some or all of the solvent) may have one or morerheological properties (e.g., melt index, melt flow rate, viscosity,melt strength, and the like) suitable for processing the polymer withknown polymer processing equipment. For example, the polymer or polymercomposition including 1,1-disubstituted alkene compounds may beprocessed using extrusion, co-extrusion, injection molding, insertmolding, co-injection molding, calendaring (e.g., using two or morerolls), blow molding, compression molding, thermoforming, rolling, spraycoating. For example, the polymeric material (i.e., the polymer or thepolymer composition) may be fed through a processing apparatus having ascrew and a barrel assembly wherein the polymeric material is conveyedalong the screw at a temperature at which the polymeric material is atleast partially in a liquid state (e.g., above any glass transitiontemperature and above any melting temperature).

The polymers according to the teachings herein preferably adhere to oneor more of the following substrates: aluminum, steel, glass, silicon, orwood. For example, when separating two substrates having the polymerplaced between the substrates, the separation of the substrates mayresult in cohesive failure of the polymer, where some polymer remains onthe surfaces of the substrates.

The polymers according to the teachings herein may be employed inextruded, blow molded, injection molded, thermoformed, or compressionmolded articles. The polymers may be employed as an adhesive. Forexample, the polymers may be employed in a pressure sensitive adhesivecomposition. The polymers may be employed as a coating, such as aprotective coating. The polymer may be employed as a primer layer over asubstrate.

Melting temperatures and glass transition temperatures are measuredusing differential scanning calorimetry on a sample of about 0.5-20.0mg. The sample is heated at a rate of about 10° C./min and then cooledat a rate of about 20° C./min.

The molecular weight is determined using gel permeation chromatography.GPC samples are prepared by first quenching with trifluoroacetic acidand then drying the polymer to remove the solvent). The dried polymer isdissolved in tetrahydrofuran (THF). About 25 μL of the dissolved polymersolution is injected into the THF eluent having a flow rate of 1 mL/min.Two columns with 5 micron, highly crosslinked polystyrene/divinylbenzenematrix particles are employed. These columns are designed to measuremolecular weights of linear polymers from 700 to 2,000,000. The columnpressure is about 65 bar and the column temperature is about 35° C. Theelution time is 30 minutes. The column is calibrated using PMMAstandards. As such, the units for molecular weight are relative based onthe standard PMMA equivalent molecular weights.

Monomer conversion is calculated using quantitative NMR. A 300 MHz NMRis employed. Any residual polymerization reaction of the polymerizationspecimen is quenched prior to NMR analysis by adding trifluoroaceticacid. The preferred solvent is CDCl₃ as it is a polar aprotic solvent.Hexamethyldisiloxane is added as an internal standard and is suitablefor these monomer compositions. The double bond intensity at about 6.45ppm is measured to determine the concentration of unconverted monomer.This double bond is a singlet for symmetrical monomers such as diethylmethylene malonate and dibutyl methylene malonate, and it is a doubletfor asymmetrical monomers such as hexyl methyl methylene malonate. FourNMR scans are run on each specimen with a 20 second delay between scans.

EXAMPLES

The 1,1-disubstituted alkene compounds employed herein are high puritymonomers, having a purity of 97 weight percent or more. The monomerseither have only trace impurities and are thus stable frompolymerization (anionic or free radical polymerization) or are providedwith a sufficient stabilizer package (e.g., about 10 ppm methanesulfonicacid and 100 ppm mono methyl ether hydroquinone) to preventpolymerization prior to the solution polymerization initiated forexample by an activator. Unless otherwise specified, the reaction timefor the polymerization reaction is about 1 hour or less.

Solution Polymerization Examples Example H-1

Fenchyl-methyl methylene malonate (F3M) is polymerized in solution. Thesolvent is tetrahydrofuran. A round bottom flask is charged with about9.0 of tetrahydrofuran and about 1.0 g of the fenchyl-methyl methylenemalonate. The mixture is stirred with a magnetic stirrer for about 5minutes. Tetramethyl guanidine (TMG) is then added to the flask toactivate the polymerization reaction. The molar ratio of monomer (F3M)to activator (TMG) is about 1000 (i.e., 1000:1). The polymerizationreaction is continued for about 1 hour at a temperature of about 23° C.The polymerization process is monitored by taking small aliquots ofsolution and quenching the reaction in the aliquot by adding an acid.After the 1 hour polymerization, a molar excess of trifluoroacetic acid(TFA) is added to the flask to quench (i.e., stop) the polymerizationreaction. An aliquot of the solution is taken and characterized by NMRspectroscopy. Another aliquot of the solution is analyzed by gelpermeation chromatography to measure the molecular weight distribution.The solution is then precipitated in cold (0° C.) methanol. The polymerprecipitates as a white powder. The precipitated polymer is filtered,dried and then characterized using Differential Scanning calorimetry(DSC). NMR spectroscopy at the end of the reaction shows no measurablepresence of residual monomer. The GPC indicates that the polymer has afirst peak in molecular weight at about 2000 and a second peak inmolecular weight at about 60,000. The polymer has a polydispersity indexof about 1.43. The glass transition temperature of the polymer is about151° C. In the homopolymerization of fenchyl-methyl methylene malonate,by varying the reaction conditions, the purity of the monomer, theactivator concentration and the reaction temperature, the molecularweight distribution of the polymer may be varied between about 1 to 8and glass transition of the polymer may be increased to be as high asabout 190° C. (e.g., when weight average molecular weight is high).

Example H-2

This example is prepared according to the method of Example H-1, exceptthe monomer is p-menthyl methyl methylene malonate (4M). The resultingpolymer has a glass transition temperature of about 126° C. The numberaverage molecular weight is about 40,000. The homopolymerization ofp-menthyl methyl methylene malonate may result in polymer having a glasstransition temperature of up to about 145° C. (e.g., by employingprocess conditions that result in higher weight average molecularweight).

Example H-3 is a polymer of diethyl methylene malonate prepared insolution. About 18 g of tetrahydrofuran solvent is added to a HDPEbottle having a PTFE coated magnetic stir bar at a temperature of about23° C. and ambient pressure. The bottle is placed on a magnetic stirplate using a mixing speed of about 800-1000 rpm. About 2 grams ofdiethyl methylene malonate monomer (DEMM) is added to the HDPE bottleand mixed to form a solution of the monomer in the solvent. After about5 minutes, about 72 microliters of tetramethylene guanidine (TMG) (at 1weight percent) in methylene chloride is added to the monomer solutionin the HDPE bottle. This corresponds to a molar ratio of monomer (DEMM)to activator (TMG) of about 2000:1. After a 1 hour reaction time, thepolymerization is terminated by adding about 0.2 ml of trifluoroaceticacid. The polymer is recovered from the solvent using the methoddescribed above for Example H-1. The molecular weight distribution ofthe resulting polymer is measured using gel permeation chromatographyand the results are shown in Table 1.

Example H-4 is prepared according to the method of preparing ExampleH-3, except the amount of the activator is reduced to about 36microliters, corresponding to a molar ratio of monomer to activator ofabout 4000:1. Example H-5 is prepared according to the method ofpreparing Example H-3, except the mount of the activator is reduced toabout 18 microliters, corresponding to a molar ratio of monomer toactivator of about 8000:1. Example H-6 is prepared according to themethod of preparing Example H-3, except the mount of the activator isreduced to about 9 microliters, corresponding to a molar ratio ofmonomer to activator of about 16000:1. Example H-7 is prepared accordingto the method of preparing Example H-3, except the mount of theactivator is reduced to about 4.5 microliters, corresponding to a molarratio of monomer to activator of about 32000:1.

Activator Examples Example A-1

A weak base may be employed to initiate the anionic polymerization of a1,1-disubstituted alkene compound. In example A-1, an activator solutionis prepared by dissolving 0.13 g of potassium benzoate and 0.428 g of acrown ether (18-crown 6) in 10 mL of dichloromethane. The molar ratio ofpotassium benzoate to the crown ether is about 1:2. It is believed thatcrown ethers may assist in solubilizing the potassium benzoate in DCM.The activator solution is used for activating the solutionpolymerization of diethyl methylene malonate (about 2 g) intetrahydrofuran (about 18 g). About 138 microliters of the activatorsolution is added to initiate the polymerization. The molar ratio ofmonomer to activator is about 1000:1. Polymerization is allowed tocontinue for 24 hours at about 23° C., and then quenched withtrifluoroacetic acid. The resulting polymer is further diluted withtetrahydrofuran for measuring the molecular weight distribution by gelpermeation chromatography. The polymer has a weight average molecularweight of about 405,700 and a number average molecular weight of about198,000.

TABLE 1 Effects of activator concentration on molecular weightdistribution Example Example Example Example Example H-3 H-4 H-5 H-6 H-7DEMM, g 2.0 2.0 2.0 2.0 2.0 THF, g 18.0 18.0 18.0 18.0 18.0 1% TMG inmethylene 75 35.5 18 9 4.5 chloride, μl DEMM:TMG 2000:1 4000:1 8000:116000:1 32000:1 Mn (daltons) 49,000 55,000 96,000 339,000 1,080,000 Mw(daltons) 259,000 252,000 334,000 642,000 2,068,000 PDI = Mw/Mn 5.4 4.63.5 1.9 1.9

Example N-1

Example N-1 is prepared by polymerizing diethyl methylene malonate atlow temperature. The polymerization is performed at about −78° C. in aSchlenk flask apparatus. All glassware is thoroughly dried by repeatedlypulling vacuum and purging with nitrogen. Freshly distilled diethylmethylene malonate monomer is stored in a sealed polypropylene bottleand degassed under vacuum prior to use. The solvent, tetrahydrofuran, istaken directly from a sealed bottle without exposing to air or moisture.The activator is secondary butyl lithium and is provided as a 1.5 Msolution in cyclohexane. The reaction temperature is maintained using adry ice/acetone freezing mixture. About 1 g of the diethyl methylenemalonate is dissolved in about 9 g of tetrahydrofuran in a round bottomflask under a nitrogen environment. After about 5 minutes, the activatorsolution was added (about 5 microliters), resulting in a molar ratio ofmonomer to activator of about 1000:1. The reaction was continued forabout 20 minutes and then terminated by adding methanol andtrifluoroacetic acid. Aliquots are removed at about 2 minutes, 6minutes, 10 minutes, and 20 minutes polymerization time. The molecularweight distribution of each aliquot is measured using gel permeationchromatography. The results are given in Table 2.

TABLE 2 Example N-1 Example N-1 Example N-1 Example N-1 2 minutes 6minutes 10 minutes 20 minutes Mn, daltons 12,750 20,980 36,940 41,280Polydispersity 2.2 1.8 1.2 1.2 Index

Example N-2

The anionic polymerization of 1,1-disubstituted alkenes may becharacterized as a living polymerization. In example N-2, the process ofExample N-1 is repeated except the amount of diethyl methylene malonateinitially added to the tetrahydrofuran solvent is about 0.25 g. Duringthe polymerization reaction, a small aliquot is removed every 2 minutesand an additional 0.25 g of the monomer is added to the reaction flask.The process is continued for about 10 minutes, when the polymer beginsto precipitate out of the solvent. The amount of activator employed isselected so that the molar ratio of the amount of monomer added in thefirst injection (i.e., 0.25 g) to the activator is about 1000:1. Themolecular weight, measured by gel permeation chromatography increasesnearly linearly:

Time (min) 0 4 6 8 10 Mn (daltons) 0 48,000 75,000 100,000 130,000

Example N-3

Example N-3 is prepared the same as Example N-2 except the amount of theactivator is increased so that the molar ratio of total monomer toactivator is about 100:1. Again, the polymer continues to grow with eachadditional charge of monomer:

Time (min) 2 4 6 8 10 Mn (daltons) 8,000 22,000 41,000 58,000 81,000

Copolymers/Random Copolymers

Example R-1

Example R-1 is a random copolymer prepared using solutionpolymerization. The method used for Example H-3 is used with thefollowing changes: (1) the 2 g of DEMM was replaced with 1 g of (P3M)and 1 g of (H3M); and (2) the amount of the 1 percent TMG activatorsolution is adjusted so that the molar ratio of the total monomer to theactivator is about 1000:1. The polymerization reaction is at about 23°C. The polymer is characterized using gel permeation chromatography anddifferential scanning calorimetry. The resulting polymer is a randomcopolymer having a single glass transition temperature of about 27.5° C.The number average molecular weight is about 7,104 daltons, and theweight average molecular weight is about 16,343 daltons, resulting in apolydispersity index, PDI, of about 2.3.

Example R-2, R-3, and R-4 are random copolymers including a firstmonomer that is a 1,1-disubstituted alkene monomer and a second monomerthat is a second 1,1-disubstituted alkene monomer. Example R-2, R-3, andR-4 are prepared using the method of Example R-1, except (1) the amountof tetrahydrofuran is about 9 g, and (2) the monomers are replaced withhexyl methyl methylene malonate (HM3) and diethyl methylene malonate(DEMM) with a ratio of HM3 to DEMM of 75:25, 50:50, and 25:75,respectively, and a total of 1 g of monomer. The polymerization iscontinued for about 1 hour at about 23° C., while mixing. Afterquenching with trifluoroacetic acid, the resulting polymer ischaracterized by gel permeation chromatography, and NMR spectroscopy.After isolating the polymer by precipitation, filtration and drying thepolymer is characterized by differential scanning calorimetry.

Example H-8, is an homopolymer prepared according to the method ofExample R-2, except the monomer is 1 g of hexyl methyl methylenemalonate monomer. The results for examples R-2, R-3, R-4, and H-8 areshown in Table 3. These examples each have a single glass transitiontemperature suggesting that R-2, R-3, and R-4 are random copolymers.

TABLE 3 Random Copolymers of hexyl methyl methylene malonate (H3M) anddiethyl methylene malonate (DEMM). Example Example Example Example H-8R-2 R-3 R-4 H3M, g 1.0 0.25 0.5 0.5 DEMM, g 0.0 0.25 0.25 0.5 Mn(daltons) 33,400 39,300 48,130 160,800 Glass transition −19.7° C. 6.6°C. −0.4° C. −34.6° C. temp, ° C. Conversion of ≈100% ≈100% ≈100% ≈100%monomer to polymer

Block Copolymer

Example B-1 is a block copolymer having four polymer blocks including 2polymer blocks (A blocks) of a first homopolymer and 2 polymer blocks (Bblocks) of a second homopolymer. The block copolymer has the structure:A-B-A-B, where each A and B is a polymer block. Block A consists of2-pheylpropyl methyl methylene malonate. Block B consists of hexylmethyl methylene malonate. A Schlenk flask is passivated with an acidsolution, rinsed with methylene chloride, and dried in an oven. About 18g of tetrahydrofuran is placed in the Schlenk flask. About 0.25 g ofmonomer A is then added to the flask. The flask is then capped with arubber septa and submerged halfway in a bath of acetone and dry icehaving a temperature of about −78° C. Vacuum was pulled on the flask andthen allowed to back fill with nitrogen. The vacuum/nitrogen back fillis repeated at least 3 times. The solution is mixed using a PTFE coatedmagnetic stir bar. Using a gas-tight microliter syringe,sec-butyllithium is added as an activator. The amount of the activatoris chosen so that the molar ratio of the initial monomer to theactivator is about 1000:1. After reacting for about 5 minutes, a smallaliquot is removed. This aliquot is quenched with trifluoroacetic acidand the molecular weight distribution of the aliquot is measured usinggel permeation chromatography. The aliquot is also characterized usingNMR spectroscopy. The polymerization is then continued by injectingabout 0.25 g of monomer B into the flask using a syringe and reactingfor about 5 minutes. A second aliquot is then removed from the flaskbefore adding a third amount of monomer (0.25 g of monomer A) into theflask using a syringe and reacting for about 5 minutes. A third aliquotis then removed from the flask before adding a fourth amount of monomer(0.25 g of monomer B) into the flask using a syringe and reacting forabout 5 minutes. A fourth aliquot is then removed. Each aliquot istreated as the first aliquot (i.e., quenched and then characterized byGPC and NMR). The results of each aliquot are shown in Table 4. Thefinal block copolymer is isolated and characterized using differentialscanning calorimetry.

TABLE 4 Properties of Example B-1 (block copolymer sample atintermediate stages) Example B-1 Example B-1 Example B-1 Example B-11^(st) aliquot 2^(nd) aliquot 3^(rd) aliquot 4^(th) aliquot Monomer A, g0.25 0.25 0.5 0.5 Monomer B, g 0.25 0.25 0.5 Mn, daltons 28,156 41,14759,243 67,400 Polydispersity 1.06 1.07 1.06 1.07 index Conversion of≈100% ≈100% ≈100% ≈100% monomer to polymer

Example S-1 is prepared according to the method of Example H-7 usingtetrahydrofuran as the solvent. The resulting polymer has a numberaverage molecular weight of about 2,000,000 daltons. Example S-2 isprepared according to the method of Example S-1, except the solvent isheptane. The resulting polymer has a number average molecular weight ofabout 500,000 daltons. Example S-3 is prepared according to the methodof Example S-1, except the solvent is toluene. The resulting polymer hasa number average molecular weight of about 200,000 daltons. Example S-4is prepared according to the method of Example S-1, except the solventis dimethoxy ethane. The resulting polymer has a number averagemolecular weight of about 700,000 daltons. Example S-5 is preparedaccording to the method of Example S-1, except the solvent isdichloromethane. The resulting polymer has a number average molecularweight of about 150,000 daltons.

Example P-1 and Example P-2 are homopolymers prepared using the methodof Example H-1, except the monomer is p-menthyl methyl methylenemalonate (4M) and the molar ratio of monomer to activator is about 100:1for Example P-1 and about 1000:1 for example P-2. The monomer employedin example P-1 has a purity of about 94.1 weight percent and the monomeremployed in example P-2 has a purity of about 98.23 weight percent.Example P-1 has a number average molecular weight of about 6,700daltons, a weight average molecular weight of about 17,400 daltons, apolydispersity index of about 2.60 and a glass transition temperature ofabout 83° C. Example P-2 has a number average molecular weight of about1,451,800 daltons, a weight average molecular of about 2,239,300daltons, a polydispersity index of about 1.62, and a glass transitiontemperature of about 145° C.

Example P-3 and Example P-4 are homopolymers prepared using the methodof Example H-1, except the monomer is fenchyl methyl methylene malonate(F3M) and the molar ratio of monomer to activator is about 100:1. Themonomer employed in example P-3 has a purity of about 92.8 weightpercent and the monomer employed in example P-2 has a purity of about98.6 weight percent. Example P-3 has a weight average molecular weightof about 40,300 daltons and a glass transition temperature of about 136°C. Example P-4 has a weight average molecular of about 290,800 daltonsand a glass transition temperature of 190° C.

Example X-1, X-2, X-3, and X-4 are all homopolymers prepared usingdiethyl methylene malonate. The polymers are prepared in solution usingtetrahydrofuran as the solvent and using monomer from the same batch.Examples X-1, X-2, and X-3 are prepared in a small scale-reactor toproduce about 1 g of polymer. Example X-4 is prepared in a largerreactor for preparing 450 g of polymer. The processing conditions forExamples X-1, X-2, X-3, and X-4 are the same, including the same ratioof monomer to activator, the same reaction time, and the same ambientconditions. Example X-4 is prepared in an 8 L round bottom flask and4.05 kg of solvent was used. After adding the monomer, the flask solventand monomer are mixed at 500 rpm to form the solution. About 0.103 ml ofpure TMG is added as the activator while mixing is continued during the1 hour reaction time. After 1 hour, the reaction was terminated with TFAand the polymer was isolated using the method of Example H-1 (i.e.precipitated in cold methanol). Over the first 15 minutes, the reactiontemperature increased by about 19° C. when preparing Example X-4. Theresults are shown in Table 5.

TABLE 5 Properties of DEMM polymer at different reactor size ExampleExample Example Example X-1 X-2 X-3 X-4 DEMM, g 1 1 1 450 DEMM, weightpercent  10%  10%  10%  10% Mn, daltons 502,800 527,300 493,700 528,400Polydispersity index 2.5 2.4 2.3 2.1 Conversion of monomer ≈100% ≈100%≈100% ≈100% to polymer

The number average molecular weight is generally expected to be highestwhen using a polar aprotic solvent. Lower number average molecularweights are generally expected to be obtained when using a nonpolarsolvent.

REFERENCE SIGNS FROM DRAWINGS

-   -   10 Solution polymerization system    -   12 Solvent    -   14 Monomer    -   16 Activator    -   26 Polymer    -   30 Illustrative steps included in a solution polymerization        process    -   32 Step of forming a solution including one or more monomers and        a solvent    -   34 Step of adding an activator to begin a polymerization        reaction    -   36 Step of propagating the polymer by an anionic polymerization        reaction    -   37 Optional step of adding one or more monomers and/or        continuously feeding one or more monomers (e.g., after        substantially all of the previously added monomer has been        consumed).    -   38 Optional step of quenching the polymerization reaction    -   40 About 6.45 ppm on the NMR spectrograph (corresponding to the        reactive double bond peak of diethyl methylene malonate)    -   42 About 0 ppm on the NMR spectrograph—internal reference    -   50 GPC peak    -   51 GPC peak area    -   52 Weight Average Molecular Weight (Mw)    -   54 Calibration curve (molecular weight v. retention time) based        on PMMA standards    -   56 58 GPC Curve

What is claimed is:
 1. A process comprising the steps of: i) mixing atleast one monomer with a solvent; ii) adding an initiator to the solventor the mixture of the solvent and the at least one monomer, wherein themolar ratio of the one or more monomers to the initiator is about 50:1or more; iii) anionically polymerizing the at least one monomer to forma polymer having a weight average molecular weight of about 3000 daltonsor more, wherein the at least one monomer includes a 1,1-disubstitutedalkene compound in solution, wherein the resulting polymer issubstantially free of a melting temperature and is substantially free ofa glass transition temperature of about 15° C. or more.
 2. The processof claim 1, wherein the polymer is a random copolymer.
 3. The process ofclaim 1, wherein the polymer is a block copolymer having a first polymerblock and a second polymer block, wherein the second polymer block andthe first polymer block have different concentration of monomers.
 4. Theprocess of claim 1, wherein the process includes a step of terminatingthe polymerization reaction.
 5. The process claim 1, wherein theresulting polymer has a polydispersity index of about 3.5 or less; andthe molar ratio of the first monomer to the initiator is about 50,000:1or less.
 6. A process comprising the steps of: i) mixing at least onemonomer with a solvent; ii) adding an initiator to the solvent or themixture of the solvent and the at least one monomer, wherein the molarratio of the one or more monomers to the initiator is about 50:1 ormore; iii) anionically polymerizing the at least one monomer to form apolymer having a weight average molecular weight of about 3000 daltonsor more, wherein the at least one monomer includes a 1,1-disubstitutedalkene compound in solution, wherein the resulting polymer is a blockcopolymer including a first block having a first glass transitiontemperature and a second polymer block having a second glass transitiontemperature, wherein the first glass transition temperature and thesecond glass transition temperature differ by about 20° C. or more. 7.The process of claim 6, wherein the block copolymer includes at leastone block having a glass transition temperature or melting temperatureof about 15° C. or more and at least one different block having nomelting temperature above 15° C. and having a glass transitiontemperature about 0° C. or less.
 8. The process of claim 5, wherein theprocess includes a step of separating the polymer from the solvent and astep of drying the polymer.
 9. The process of claim 1, wherein the oneor more monomers includes one or more monomers selected from the groupconsisting of methyl propyl methylene malonate, dihexyl methylenemalonate, di-isopropyl methylene malonate, butyl methyl methylenemalonate, ethoxyethyl ethyl methylene malonate, methoxyethyl methylmethylene malonate, hexyl methyl methylene malonate, dipentyl methylenemalonate, ethyl pentyl methylene malonate, methyl pentyl methylenemalonate, ethyl methoxyethyl methylene malonate, ethoxyethyl methylmethylene malonate, butyl ethyl methylene malonate, dibutyl methylenemalonate, diethyl methylene malonate (DEMM), diethoxyethyl methylenemalonate, dimethyl methylene malonate, di-n-propyl methylene malonate,ethyl hexyl methylene malonate, fenchyl methyl methylene malonate,menthyl methyl methylene malonate, 2-phenylpropyl ethyl methylenemalonate, and dimethoxyethyl methylene malonate.
 10. The process ofclaim 1, wherein the 1,1-disubstituted alkene compound is provided as ahigh purity monomer having a purity of about 95 weight percent or more,based on the total weight of the high purity monomer.
 11. A processcomprising the steps of: i) mixing at least one monomer with a solvent;ii) adding an initiator to the solvent or the mixture of the solvent andthe at least one monomer, wherein the molar ratio of the one or moremonomers to the initiator is about 50:1 or more; iii) anionicallypolymerizing the at least one monomer to form a polymer having a weightaverage molecular weight of about 3000 daltons or more, wherein the atleast one monomer includes a 1,1-disubstituted alkene compound insolution, wherein the polymer is a homopolymer, and the method includesa step of separating the polymer from the solvent and the homopolymer issubstantially free of a melting temperature and is substantially free ofa glass transition temperature of about 15° C. or more.
 12. The processof claim 11, wherein the homopolymer has a polydispersity index of 1.5or less and/or a weight average molecular weight greater than 20,000g/mole.
 13. A process comprising the steps of: i) mixing at least onemonomer with a solvent; ii) adding an initiator to the solvent or themixture of the solvent and the at least one monomer, wherein the molarratio of the one or more monomers to the initiator is about 50:1 ormore; iii) anionically polymerizing the at least one monomer to form apolymer having a weight average molecular weight of about 3000 daltonsor more, wherein the at least one monomer includes a 1,1-disubstitutedalkene compound in solution; wherein the process includes a step ofdepositing a solution onto a substrate, the solution including a polymerresulting from the polymerization step; and a step of evaporating someor all of the solvent so that the substrate is partially or entirelycoated with a layer of the polymer; wherein the initiator includes asalt selected from a benzoate, an acetate, a silicate, or a carbonate;and wherein the polymer is a random copolymer.
 14. The process of claim13, wherein the one or more monomers includes one or more monomersselected from the group consisting of methyl propyl methylene malonate,dihexyl methylene malonate, di-isopropyl methylene malonate, butylmethyl methylene malonate, ethoxyethyl ethyl methylene malonate,methoxyethyl methyl methylene malonate, hexyl methyl methylene malonate,dipentyl methylene malonate, ethyl pentyl methylene malonate, methylpentyl methylene malonate, ethyl methoxyethyl methylene malonate,ethoxyethyl methyl methylene malonate, butyl ethyl methylene malonate,dibutyl methylene malonate, diethyl methylene malonate (DEMM),diethoxyethyl methylene malonate, dimethyl methylene malonate,di-n-propyl methylene malonate, ethyl hexyl methylene malonate, fenchylmethyl methylene malonate, menthyl methyl methylene malonate,2-phenylpropyl ethyl methylene malonate, and dimethoxyethyl methylenemalonate.
 15. The process of claim 6, wherein the one or more monomersincludes one or more monomers selected from the group consisting ofmethyl propyl methylene malonate, dihexyl methylene malonate,di-isopropyl methylene malonate, butyl methyl methylene malonate,ethoxyethyl ethyl methylene malonate, methoxyethyl methyl methylenemalonate, hexyl methyl methylene malonate, dipentyl methylene malonate,ethyl pentyl methylene malonate, methyl pentyl methylene malonate, ethylmethoxyethyl methylene malonate, ethoxyethyl methyl methylene malonate,butyl ethyl methylene malonate, dibutyl methylene malonate, diethylmethylene malonate (DEMM), diethoxyethyl methylene malonate, dimethylmethylene malonate, di n propyl methylene malonate, ethyl hexylmethylene malonate, fenchyl methyl methylene malonate, menthyl methylmethylene malonate, 2-phenylpropyl ethyl methylene malonate, anddimethoxyethyl methylene malonate.
 16. The process of claim 13, whereinan acid compound is employed so that a pH of the mixture of the solventand monomer at a start of the polymerization is from about 5 to about 7.17. The process of claim 11, wherein the homopolymer has apolydispersity index of 1.5 or less; the homopolymer has a weightaverage molecular weight greater than 20,000 g/mole; the initiatorincludes a salt including a benzoate, an acetate, a silicate, or acarbonate; an acid compound is employed so that a pH of the mixture ofthe solvent and monomer at a start of the polymerization is from about 5to about 7; and the monomer is methyl propyl methylene malonate, dihexylmethylene malonate, di-isopropyl methylene malonate, butyl methylmethylene malonate, ethoxyethyl ethyl methylene malonate, methoxyethylmethyl methylene malonate, hexyl methyl methylene malonate, dipentylmethylene malonate, ethyl pentyl methylene malonate, methyl pentylmethylene malonate, ethyl methoxyethyl methylene malonate, ethoxyethylmethyl methylene malonate, butyl ethyl methylene malonate, dibutylmethylene malonate, diethyl methylene malonate (DEMM), diethoxyethylmethylene malonate, dimethyl methylene malonate, di-n-propyl methylenemalonate, ethyl hexyl methylene malonate, fenchyl methyl methylenemalonate, menthyl methyl methylene malonate, 2-phenylpropyl ethylmethylene malonate, or dimethoxyethyl methylene malonate.